1. Field of the Invention
The present invention relates to a sheet medium conveying device, an image forming apparatus, and a sheet medium conveying method.
2. Description of the Related Art
Some conventional sheet media, such as label sheets or tag sheets, have marks, such as black marks or notches, provided at regular intervals in conveying directions in which the sheet media are conveyed. Sheet medium conveying devices that handle such sheet media are configured to control conveyance of a sheet media while detecting the marks with a sensor and identifying the position (or conveyance position) of the sheet medium on the basis of the positions of the marks. Hereinafter, the marks will be referred to as position detection marks.
As one of these sheet medium conveying devices, there has been proposed a sheet medium conveying device that has a mode in which the conveyance position of the sheet medium is identified on the basis of the positions of the position detection marks and a mode in which the conveyance position of the sheet medium is identified by conveying the sheet medium by a predetermined amount at a time, and when an error occurs during operating in one of the modes, continues its operation by operating in the other mode (see, e.g., Japanese Patent Application Publication No. 2008-238484).